Mechanical load bearing device

ABSTRACT

A load bearing device for supporting ceilings during repair, said load bearing device including: a base having at least one support; a lifting means connected to said base, said lifting means including an operating mechanism used to operate said lifting means and an elongate extension means having a lower end and a upper end; a pressure plate mounted on said upper end of said elongate extension means to apply a load to and raise a portion of said ceiling when said lifting means is operated; said lifting means being arranged to move through a predetermined distance, the distance being substantially equivalent to a typical sagging distance, the lifting means being arranged to indicate to a user when it has moved through the predetermined distance.

FIELD OF THE INVENTION

The present invention is related to a mechanical load bearing device, in particular a mechanical load bearing device for the vertical hoisting of ceilings by a single person.

BACKGROUND OF THE INVENTION

There are many designs available for vertical lifting equipment, however much of the equipment available is not readily manoeuvrable with a load in place and many require the operator to use both hands to lift and manoeuvre the device, whereby the load being lifted is either unattended or additional people are required to complete the operation.

In the construction industry, by way of example, it is often required to repair ceilings which over time have sagged. When such a ceiling sags over time, the plasterboard ceiling will typically set (goes hard) in the position to which it has sagged. If the plasterboard and ceiling are not repaired the ceiling will eventually fall down causing major damage to other sections of the ceiling and the contents below. To lift the ceiling back to the desired horizontal position and hold it in place while the ceiling is repaired would require several workers. It is firstly apparent that such workers are not effectively used. Secondly it takes several workers to place props in position to hold the ceiling in place and this requires substantial physical effort to push a sagged ceiling back into place. The props are normally used to hold the ceiling once it is in the required position to be repaired so further substantial physical effort is required to lift and hold a ceiling prior to placement of the props.

There are also several devices known which allow the overhead installation of plasterboard panels and cornices. In the construction of a ceiling, a plasterboard panel is lifted into place and supported by a panel hoisting and positioning device. The device allows the panel to be held effectively and positively in place while the panel is fixed to the rafters in the ceiling. These devices are designed to place and support a sheet of plasterboard in a position to be fixed to the ceiling rafters, they do not require the device to be able to apply substantial force to the plasterboard as it is only required to support the plasterboard while it is fixed to the ceiling.

With the installation of cornices it is generally recognised that the process requires the use of at least two operators in order to install a standard ceiling cornice. However, it is possible to install a lightweight cornice using only one person. This installation is carried out by means of driving a large 4 inch nail into the wall at the opposite end of the cornice which would have normally been held by the other operator to hold the cornice in place. This method of installing lightweight cornices is not acceptable for solid plaster walls as it causes extensive damage to wall and requires the wall to be repaired once the cornice has been installed. There is also the problem that the nail which is holding the cornice may come out before the cornice is properly installed and thereby damage the cornice. As stated above this method of installation is only appropriate for lightweight (gyprock) cornice, it cannot be used for heavier (plasterglass) cornice.

Also known in the construction industry are vertical lifting devices which allow materials such as kitchen cabinets to be installed along vertical walls. The devices are used to lift and support the materials while the materials are fixed in place to the wall, they are not required to apply a substantial force to the materials as they are only required to support and hold the materials. The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of admission that the prior art forms part of the common general knowledge in Australia.

Any discussion of documents, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art.

SUMMARY OF THE INVENTION

The present invention provides a load bearing device for supporting ceilings during repair, said load bearing device including:

a base having at least one support;

a lifting means connected to said base, said lifting means including an operating mechanism used to operate said lifting means and an elongate extension means having a lower end and a upper end;

a pressure plate mounted on said upper end of said elongate extension means to apply a load to and raise a portion of said ceiling when said lifting means is operated;

said lifting means being arranged to move through a predetermined distance, the distance being substantially equivalent to a typical sagging distance, the lifting means being arranged to indicate to a user when it has moved through the predetermined distance.

In another embodiment the present invention provides a load bearing device for supporting ceilings during repair, said load bearing device including:

a tripod base having a plurality of legs each having an upper end and a lower end, a wheel connected to the lower end of each leg to allow the device to be manoeuvrable;

a support having a top end and a bottom end, said plurality of legs attached to said support;

a lifting means including an operating mechanism used to operate said lifting means and said lifting means is connected to said top end of said support, said lifting means including:

-   -   a release mechanism to allow the lifting means to retract after         use;     -   an elongate extension means having a lower end and a upper end,         said lower end connected to said lifting means;

a pressure plate attached to said upper end of said elongate extension means to apply a load to and raise a portion of said ceiling when said lifting means is operated;

wherein said lifting means being arranged to move through a predetermined distance, the distance being substantially equivalent to a typical sagging distance, the lifting means being arranged to indicate to a user when it has moved through the predetermined distance.

The present invention overcomes the problems of the prior art by providing a mechanical load bearing device which is easily operated by a single person. The device allows a single operator to repair a sagging ceiling without the requirement of an assistant. For example, once a ceiling has been re-positioned by the mechanical load bearing device the single operator is then easily able to use such devices as an auto-collating screw gun to fix the ceiling back to its original position. The device also allows the repair to be carried out using less physical effort as the device is used to hoist the sagging ceiling and also hold the ceiling while the repair is carried out. Finally the device allows the operator to perform the repair in substantially less time than had previously been required to repair a ceiling.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.

FIG. 1 is an isometric view of a mechanical load bearing device according to one embodiment of the present invention.

FIG. 2 is an exploded isometric view showing the separated main components of a mechanical load bearing device according to one embodiment of the present invention.

FIG. 3 shows a mechanical load bearing device positioned in preparation for use in repairing a sagging ceiling according to one embodiment of the present invention.

FIG. 4 shows a mechanical load bearing device positioned in preparation to hoist the ceiling according to one embodiment of the present invention.

FIG. 5 shows a mechanical load bearing device after having hoisted the sagging ceiling and holding the ceiling in place so as the operator may repair the ceiling according to one embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENT

The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of a mechanical load bearing device according to the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details.

FIG. 1 shows the mechanical load bearing device 10 assembled in preparation for use. The mechanical load bearing device 10 provides an improved method of repairing sagging ceilings 50. When a ceiling 50 sags over time, the plasterboard ceiling will typically set (goes hard) in the position to which it has sagged. For example a typical distance which a ceiling would sag to would be a distance in the range of 2 cm to 8 cm. It therefore requires a significant amount of force to re-position a sagged and set ceiling back to its original position. The device 10 allows the operator to repair a ceiling 50 without the need for another person who would normally be required to push up the sagging ceiling 50 manually with a wooden or similar type prop. It can be seen that the use of the mechanical load bearing device 10 will simplify the ease in which the task of repositioning a ceiling panel which has sagged is accomplished.

FIGS. 1 and 2 shows a mechanical load bearing device 10 including three main components, a base 20, a lifting means 30 and a pressure plate assembly 40. FIG. 2 shows an exploded view of the three components. The base 20 includes three identical supports 27 welded onto shaft 22. In this preferred arrangement the base 20 includes three supports 27 arranged in a tripod configuration, however the device 10 is not limited to this number and configuration of supports 27, it may for example have four supports 27 to define a shape of a square.

Each support 27 ideally has a wheel 21 attached to the bottom of each leg 27 to allow the mechanical load bearing device 10 to be moved. The wheels 21 also include a lock 28 to prevent the wheels 21 and subsequently the device 10 from moving when the locks 28 are engaged.

A lifting means 30 is mounted on the top end of the shaft 22 to a flat metal plate 23. The lifting means 30 may include a bottle jack 25 and an elongate extension means 31. The lifting means 30 provides the higher pressure required to repair a sagged ceiling. The high pressure required is significantly more than what known panel lifters and other similar devices used in the industry are capable of producing and therefore does not allow for the substitution of known panel lifters or other similar known devices to repair sagged ceilings. A further requirement for the lifting means 30 is that it must only have a short lift in order to lift a ceiling 50 which requires repositioning and repairing. The short lift is required as a ceiling will generally only sag a distance of 8 cm, once the plasterboard has set in this position it requires a short lift and a high pressure lift in order to repair the sagged ceiling. There is also the added advantage that by having only a short lift the load bearing device 10 and the lifting means 30 can be quickly retracted to enable the user to move on to further repairs and also provides the time saving factor for the overall job. Alternatively the bottle jack 25 may include a screw jack or a combination hydraulic/air jack to lift and repair the ceiling 50.

The bottle jack 25 is secured to the plate 23 by bolts (not shown) or similar securing devices. The bottle jack 25 has been modified so as to extend the operating mechanism 26, for example a handle to allow for one-handed operation. The bottle jack 25 also includes a pressure release valve (not shown) which is operated by mechanism 24. The mechanism 24 is in the shape of a t-bar, however, alternatively it could form any shape which allows the user to easily release the pressure in the bottle jack 25.

To mount the elongate extension means 31 to the bottle jack 25 a short housing spigot 60 is welded to the hydraulic shaft 29 of the bottle jack 25. It should also be noted that other methods of attaching the short housing spigot 60 to the bottle jack 25 and the hydraulic shaft 29 may be used such as a simple screw thread on the bottle jack 25 and a mating screw thread on the short housing spigot 60. The housing spigot 60 has an aperture 61, when the lower end of the elongate extension means 31 is placed over the spigot 60 the aperture 61 lines up with aperture 33 in the elongate extension means 31 and a bolt 34 is passed through both apertures 61, 33 to secure the elongate extension means 31 to the spigot 60. This allows the elongate extension means 31 to be easily disassembled from the bottle jack 25 for transport and storage.

At the upper end of the elongate extension means 31 a bolt hole 35 and fixing pin 32 enable the pressure plate assembly 40 to be inserted into the upper end of the elongate extension means 31 and secured by use of the fixing pin 32. The T-bar 41 has several height adjustment holes 42 which enable the user to vary the overall height of the mechanical load bearing device 10 for the repair of different ceiling 50 heights. It is also possible to incorporate different length T-bar assemblies 41 to vary the overall height of the mechanical load bearing device 10.

On the T-bar cross-member 43 a flat rectangular aluminium plate 44 is mounted to the T-bar cross member 43 by screws (not shown) which are countersunk into the aluminium plate 44 so that they do not appear above the surface of the aluminium plate 44. Alternatively the rectangular aluminium plate 44 can be attached to the T-bar cross-member 43 by any other suitable means, for example it may be welded. To reinforce the aluminium plate 44 the T-bar cross member 43 is preferably constructed from a open box channel which is fixed to the underside of the aluminium plate 44. The open box channel is used to strengthen the plate and provide for the distribution of weight over a greater cross-sectional area when the mechanical load bearing device 10 is used to push up a sagging ceiling 50.

The four corners of the aluminium plate 44 are rounded. The aluminium plate 44 is the flat member which comes into contact with the ceiling 50. The contacting portion of the plate 44 which comes into contact with the ceiling 50 is substantially planar so as it easily distributes the pressure across the portion of the ceiling 50 to be lifted and repaired. The aluminium plate 44 is sized so as to span three rafters which are 450 cm apart from the centre of each rafter to the centre of the next rafter.

To repair a sagging ceiling 50 the operator of the mechanical load bearing device 10 must first make an estimation of the height of the ceiling 50 to be repaired. The estimation is carried out by lifting the pressure plate assembly 40 manually until it is located just below the centre of the concave part 51 of the ceiling 50 to be repaired (see FIG. 3). Then using the adjustment holes 42 on the pressure plate assembly 40 of the mechanical load bearing device 10, the operator then inserts the fixing pin 32 in the required position. The operator then positions the whole device in place under the ceiling to be repaired (see FIG. 4) and locks the wheels 21 by engaging the wheel locks 28. The ceiling 50 is then hoisted by pushing up and down on the operating mechanism 26 of the bottle jack 25 in the usual manner. The operator continues up and down pumping action on the operating mechanism 26 until the ceiling 50 is back in place against the rafters 52 (see FIG. 5). The operator can tell when the ceiling 50 is firmly positioned against the rafters 52 due to the resistance which will be felt in the operating mechanism 26 of the bottle jack 25. For an operator to determine when the ceiling 50 is in the correct position against the rafters 52, a combination of feeling the resistance in the operating mechanism 26 which is used to indicate to the user that the ceiling is in the correct position and also the very short lift in the lifting means 30, for example the bottle jack 25 has a very short lift, and high pressure to enable the operator to repair a ceiling 50, especially when the ceiling has sagged and set in the sagged position. For example a typical distance which a ceiling would sag, would be a distance in the range of 2 cm to 8 cm. The operator makes the required repair and once this is achieved the pressure releasing valve is released by turning mechanism 24 on the bottle jack 25. When the pressure is released the elongate extension means 31 and pressure plate assembly 40 are lowered and the whole mechanical load bearing device 10 can be relocated to the next position requiring repair.

A mechanical load bearing device 10 according to the present invention may also be used to repair or replace damaged cornices or install a new cornice to a ceiling 50 in a similar manner as described above. The device 10 allows the operator to repair and install long and heavy lengths of cornice without the need for another operator who would normally be required to install a standard ceiling cornice. It can be seen that the use of a mechanical load bearing device 10 according to the present invention will simplify the ease in which the task of repositioning a ceiling cornice is accomplished.

A mechanical load bearing device 10 according to the present invention may also be used to repair steel rafter ceilings were the distance between steel trusses is usually between 1.5 to 1.8 metres. To repair this type of ceiling more than one mechanical load bearing device 10 can be used with the two pressure plate assemblies 40 placed side by side to cover the span of the steel trusses.

Although the present invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omission and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodied within a scope encompassed and equivalent thereof with respect to the feature set out in the appended claims. 

1. A load bearing device for supporting ceilings during repair, said load bearing device including: a base having at least one support; a lifting means connected to said base, said lifting means including an operating mechanism used to operate said lifting means and an elongate extension means having a lower end and a upper end; a pressure plate mounted on said upper end of said elongate extension means to apply a load to and raise a portion of said ceiling when said lifting means is operated; said lifting means being arranged to move through a predetermined distance, the distance being substantially equivalent to a typical sagging distance, the lifting means being arranged to indicate to a user when it has moved through the predetermined distance.
 2. The device of claim 1, wherein said at least one support includes a leg attached to said base.
 3. The device of claim 1, wherein said at least one support includes three legs configured as a tripod.
 4. The device of claim 1, wherein said base further includes a single tube connected to said lifting means.
 5. The device of claim 1, wherein said operating mechanism includes a handle or similar device.
 6. The device of claim 1, wherein said plurality of supports further include a wheel connected to a lower end of each support to allow the device to be manoeuvrable.
 7. The device of claim 6, wherein said wheels include a locking mechanism to prevent the load bearing device from movement when in use.
 8. The device of claim 1, wherein said lifting means further includes a release mechanism to allow the lifting means to retract after use.
 9. The device of claim 8, wherein said lifting means is a bottle jack.
 10. The device of claim 8, wherein said lifting means is a combination hydraulic/air jack.
 11. The device of claim 1, wherein said elongate extension means includes a number of spaced apart height adjustment holes located spaced from said upper end of said elongate extension means to allow for the adjustment in height of said load bearing device for different height ceilings.
 12. The device of claim 11, wherein said elongate extension means includes different length elongate extension means to vary the overall height of the load bearing device.
 13. The device of claim 8, wherein said lifting means further includes a spigot attached to said lifting means for attaching to said lower end of said elongate extension means.
 14. The device of claim 1, wherein said pressure plate is a flat rectangular plate.
 15. The device of claim 1, wherein said pressure plate is dimensioned to be 1130 mm in length to span three rafters having a standard 450 centimetres span from the centre of each rafter to the centre of the next rafter.
 16. A load bearing device for supporting ceilings during repair, said load bearing device including: a tripod base having a plurality of legs each having an upper end and a lower end, a wheel connected to the lower end of each leg to allow the device to be manoeuvrable; a support having a top end and a bottom end, said plurality of legs attached to said support; a lifting means including an operating mechanism used to operate said lifting means and said lifting means is connected to said top end of said support, said lifting means including: a release mechanism to allow the lifting means to retract after use; an elongate extension means having a lower end and a upper end, said lower end connected to said lifting means; a pressure plate attached to said upper end of said elongate extension means to apply a load to and raise a portion of said ceiling when said lifting means is operated; wherein said lifting means being arranged to move through a predetermined distance, the distance being substantially equivalent to a typical sagging distance, the lifting means being arranged to indicate to a user when it has moved through the predetermined distance.
 17. The device of claim 16, wherein said pressure plate is dimensioned to be 1130 mm in length to span three rafters having a standard 450 centimetres span from the centre of each rafter to the centre of the next rafter.
 18. The device of claim 15, wherein said elongate extension means includes a number of spaced apart height adjustment holes located spaced from said upper end of said elongate extension means to allow for the adjustment in height of said load bearing device for different height ceilings.
 19. The device of claim 17, wherein said elongate extension means includes different length elongate extension means to vary the overall height of the load bearing device. 